Contrast enhancement during hepatic computed tomography: effect of total body weight, height, body mass index, blood volume, lean body weight, and body surface area.

OBJECTIVE: The objective of this study was to evaluate the effect of total body weight, height, body mass index, blood volume, lean body weight, and body surface area (BSA) on aortic and hepatic contrast enhancement during hepatic computed tomography (CT).
METHODS: We calculated the changes in the CT number per gram of iodine ((Δ Hounsfield units/g [ΔHU/g])) for the aorta and the liver during portal venous phase. We performed linear regression analyses between ΔHU/g and each of the body parameters.
RESULTS: ΔHU/g and BSA showed the strongest inverse correlation. The correlation coefficients for the aorta and liver were 0.70 and 0.68 for ΔHU/g and total body weight, 0.41 and 0.37 for height, 0.54 and 0.55 for body mass index, 0.68 and 0.59 for blood volume, 0.70 and 0.62 for lean body weight, and 0.71 and 0.68 for BSA, respectively (P < 0.001 for all).
CONCLUSION: Our study supports the use of a protocol with iodine dose adjusted for the patient BSA.